03391nam a2200409 4500 20260818093859.0 130598 th eng .b11589449 AIT Thesis no.AE-96-11 Guo, Xuan The direct fermentative production of lactic acid using various starch sources Bangkok : Asian Institute of Technology, 1996 76 leaves + 1 online resource Thesis ; no. AE-96-11 A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering Thesis (M.Eng.) - Asian Institute of Technology, 1996 One-step direct fermentative production of lactic acid from different starch sources using L. amylovorus was studied compared to two-step fermentation (saccarification followed by fermentation) using L. delbrueckii from starch in terms of lactic acid yield and productivity. Tuber starch like cassava and potato starch (1 %) gave poor lactic acid production at 4.72 and 4.42 g/L concentration, while cereal starch like corn. rice and wheat starch (1 %) gave lactic acid production at 10.05, 7.819 and 7.85 g/L respectively. Amylase enzyme activity was not the limiting factor during cassava starch fermentation as it was produced in sufficient quantity. Glucose repression occurs when glucose concentration is above 1 %. however. glucose accumulation during fermentation of cassava starch was less than 1 %. Vitamin B complex. calcium ion. yeast extract level and pH were found no significant effect on lactic acid production from cassava starch. Combination of peptone. beef extract and yeast extract can improve the lactic acid production to 8.28 g/L with conversion rate of 74.6% compared to 4.72 g/L with conversion rate of 42.5% from 1 % cassava starch. This result shows that there are some components present in corn starch, which is similar to peptone or beef extract. can stimulate the lactic ac id production. One-step fermentation can reduce the total time to half for lactic ac id production from starch compared to a two-step fermentation. It also eliminates the cost of enzyme associated to starch hydrolysis and reduces the number of reactors involved in the entire process. Fermentation Rakshit, Sudip Kumar, Chairperson Athapol Noomhorm, Examination Committee Jindal, Vinod Kumar, Examination Committee Stevens, Willem Frans, Examination Committee Vincent, Jean-Claude, Examination committee State Education Committee of China, Scholarship donor Asian Institute of Technology. Thesis ; no. AE-96-11 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B14516 .b11589449 mnait v 240329 0 970320 m a v 4 mnait mnarc 22 40 Barcode : 30050120577696 CREATED : 1997-03-20 RECORD # : i11922321 LPATRON : 1017165 LCHKIN : 2006-09-21 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 3 TOT RENEW : 2 Barcode : 30050120372304 CREATED : 2016-02-06 RECORD # : i13011248 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 30493 30493 0 0 0 0 MAIN MAIN mnait 2026-08-18 0 AIT Thesis no.AE-96-11 30050120577696 2026-08-18 09:38:59 3 2026-08-18 22 0 0 0 0 MAIN MAIN mnarc 2026-08-18 0 AIT Thesis no.AE-96-11 30050120372304 2026-08-18 09:38:59 2026-08-18 40